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Description/Abstract

The reactions of Cu(NO3)2, Co(NO3)2 and Ni(NO3)2 with bp_pen = 1,5-bis(4-pyridyl)pentane yield three-dimensional coordination polymers [M(bp_pen)2(NO3)2] with M = Cu ( 1), Co ( 2), Ni ( 3). These are four-connected uninodal 3D nets exhibiting a rare (65.8) topology defined by metal centres (nodes) and bipyridyl ligands (edges). The reaction of CuNO3 with bp_hep = (1,7-bis(4-pyridyl)heptane yielded a similar net in the structure of [Cu2(bp_hep)4(NO3)3](NO3)(H2O) ( 4). A characteristic of the networks of 1– 4 is that their shortest edge is by far (50%) longer than the shortest distance between two neighbouring nodes. This unusual geometrical feature is facilitated by the long and flexible bp_pen and bp_hep spacers. All four investigated crystal structures are composed of three interpenetrating (65.8) nets.